1985

Unsaturated carboxylic acids such as meth- acrylic acid, crotonic acid, vinylacetic acid, and sorbic acid and aromatic carboxylic acids reacted with terminal ace- tylenes in the presence of a catalytic amount of bis(05- cyclooctadieny1)ruthenium-P-n-Bui3n benzene a t 80 "C to give enol esters having a terminal methylene group in excellent yields with high regioselectivity.

2,4,6-trimethylbenzoyldiphenylphosphineoxide (TMDPO) was irradiated in dilute solutions of benzene, methanol and dichloromethane with 20 ns flashes of 347 nm light. By optical absorption measurements, a transient spectrum with a maximum at about 330 nm detected at the end of the flash was ascribed to the diphenyl phosphonyl radical . This radical is formed by the reaction. Evidence was obtained for fragment radicals being formed, to some extent at least, from triplet states. Both the singlet and the triplet lifetimes were estimated as τ < 1 ns.

Cyanoacrylate adhesive compositions containing (a) a toughener (e.g., a core-shell copolymer such as an MBS, ABS, or MABS copolymer), the toughener optionally being treated to remove impurities which cause premature polymerization of cyanoacrylates, and (b) cyanoacrylate-compatible, toughener-compatible sustainer (e.g., an organic compound containing one or more unsubstituted or substituted aryl groups, such as diphenylmethane or dichlorobenzene). The inclusion of sustainer provides improved retention of toughness after heat aging of cured bonds of the adhesive.

Zum Verkleben von porösen und saugfähigen Werkstoffen, wie z.B. Papier, Textilen, soll Zyanakrylatkleber in schaumförmigen Zustand auf die Klebstelle aufgetragen werden.

Damit lassen sich die Vorteile des schnell abbindenden Zyanakrylatklebers auch auf die Verklebung von porösen Werkstoffen übertragen, außerdem ergibt sich eine optimal dünne Fuge bei hoher Abbindegeschwindigkeit bei sparsamem und damit preisgünstigenm Auftrag des Klebers.

Latent fingerprints are developed by exposing them to vapours generated from a thin film of a storage stable cyanoacrylate monomer and a thixotropic additive in sufficient amount to render the composition substantially non-flowable. The monomer film should have a surface area at least 129 sq. cm.

An envelope package for the monomer composition has inner polyethylene surfaces. The envelope may be peeled open to expose the inner surfaces coated with a film of the composition.